Cytokines play an important role in the pathophysiology of ulcerative colitis and Crohn's disease. As a transcriptional activator of genes encoding inflammatory cytokines, NF-kB may be an important effector molecule in both ulcerative colitis and Crohn's disease and may also be a target for antiinflammatory intervention. In unstimulated cells, NF-kB resides in the cytoplasm in an inactive complex bound to the inhibitor IkB-a. Multiple stimuli, including endotoxin, cytokines, and reactive oxygen intermediates cause release of IkB. NF-kB then enters the nucleus, binds to DNA control elements, and induces transcription. NF-kB activation has been blocked by antioxidants such as vitamin E (vit E) and glutathione (GSH)-enhancing agents, and by anti-inflammatory agents, such as glucocorticoids, mesalamine, and cyclosporine. It is our working hypothesis that NF-kB and NF-kB-inducible cytokines (TNF, IL-1, IL-6, IL- 8) play an etiologic role in the intestinal injury and many of the clinical/biochemical abnormalities observed in ulcerative colitis and Crohn's disease. The overall objectives of this laboratory are to further define mechanisms and modulatory pathways whereby cytokines, such as TNF, IL-1 and IL-8 induce metabolic disturbances and intestinal injury in IBD, with the ultimate goal being development of specific "anticytokine" therapy for IBD. In this proposal, we will examine the role of NF-kB activation and cytokine production in the intestinal inflammation of IL- 10-deficient (IL-10T) mice, and we will evaluate whether or not inhibition of NF-kB activation attenuates the inflammation. We next will determine whether pharmacological modulation or blockade of NF-kB activation affects cytokine production in lamina propria monocytes and splenic moncytes isolated from IL-10 deficient mice. Finally, we will examine the role of specific transcription factors (NF-kB and NF-IL-6) in the inducible activation of the IL-8 gene in the human intestinal epithelial cell line, Caco-2. These studies should provide new insights into mechanisms of cytokine-mediated injury in intestinal inflammatory states, and this information may assist in development of new forms of therapy for inflammatory bowel disease. I have great enthusiasm and dedication for a career in academic gastroenterology, and a focused research experience in cytokines/molecular biology will greatly enhance my chances of success. Dr. McClain is a highly experienced mentor who has developed a program for Dr. Varilek that will provide the resources, training, and guidance necessary to achieve success.